New to Telerik UI for ASP.NET AJAX? Download free 30-day trial

Events Overview

The RadInput controls support a number of client-side events that let you respond to user actions without a postback. The following table lists the various client events, and which controls they apply to:


Event Applies to Description
OnValueChanging RadTextBox , RadNumericTextBox , and RadDateInput Occurs when the control loses focus after the user has changed its value, before the new value is assigned.
OnValueChanged all RadInput controls Occurs after a new value has been assigned when the control loses focus.
OnFocus all RadInput controls Occurs when the control gets focus, if it is not ReadOnly.
OnBlur all RadInput controls Occurs when the control loses focus, if it is not ReadOnly.
OnButtonClick all RadInput controls Occurs when the user clicks on the button that is associated with the input control.
OnKeyPress all RadInput controls. Occurs when the user presses a key to enter a value.
OnDisable all RadInput controls Occurs when the control is disabled.
OnEnable all RadInput controls Occurs when the control is enabled.
OnLoad all RadInput controls Occurs when the control is loaded on the client.
OnMouseOver all RadInput controls Occurs when the mouse enters the input area.
OnMouseOut all RadInput controls Occurs when the mouse leaves the input area.
OnClientPasswordStrengthCalculating RadTextBox and RadInputManager with a TextBoxSetting Occurs when using the password strength check feature and changing the text, before the indicator is updated.

To use these events, simply write a javascript function that can be called when the event occurs. Then assign the name of the javascript function as the value of the the corresponding property.

<script type="text/javascript">
    function OnTextError(sender, args)
        var message = "Invalid character - " + args.get_newValue();
<telerik:RadTextBox RenderMode="Lightweight" ID="RadTextBox1" runat="server"
    <ClientEvents OnError="OnTextError" />

You can also assign event handlers in client-side code. When using the client-side API, pass a reference to the event handler rather than its name. One advantage of using the client-side API is that you can attach multiple event handlers to one event using the standard MS AJAX convention:

function onClickHandler1()
    alert("First handler called");
function onClickHandler2()
    alert("Second handler called");
function pageLoad()
    var inputControl = $find('<%=RadInput1.ClientID%>');

Another advantage of the client-side API is that you can detach an event handler dynamically:

function removeOnClick2()
    var inputControl = $find('<%=RadInput1.ClientID%>');

Note that on the client-side, the names of events are slightly different than on the server side. The following table shows the correspondence between client-side and server-side names:


Server-Side Name Client-SideName Methods to add and Remove
OnValueChanging valueChanging add_valueChanging, remove_valueChanging
OnValueChanged valueChanged add_valueChanged, remove_valueChanged
OnFocus focus add_focus, remove_focus
OnBlur blur add_blur, remove_blur
OnButtonClick buttonClick add_buttonClick, remove_buttonClick
OnKeyPress keyPress add_keyPress, remove_keyPress
OnDisable disable add_disable, remove_disable
OnEnable enable add_enable, remove_enable
OnError error add_error, remove_error
OnLoad load add_load, remove_load
OnMouseOver mouseOver add_mouseOver, remove_mouseOver
OnMouseOut mouseOut add_mouseOut, remove_mouseOut
OnMoveDown moveDown add_moveDown, remove_moveDown
OnMoveUp moveUp add_moveUp, remove_moveUp
OnEnumerationChanged enumerationChanged add_enumerataionChanged, remove_enumerationChanged

See Also

In this article